But here must be added a strict and earnest caution, that those only are to be taken for conformable and analogous instances which indicate (as I said at the beginning) physical resemblances, that is, real and substantial resemblances; resemblances grounded in nature, not accidental or merely apparent; much less superstitious or curious resemblances, such as the writers on natural magic (very frivolous persons, hardly to be named in connection with such serious matters as we are now about) are everywhere parading — similitudes and sympathies of things that have no reality, which they describe and sometimes invent with great vanity and folly.

For in the first place, since for the most part they depend upon the expression, they put us in a better condition for seeing in how many senses any term is used, and what kind of resemblances and what kind of differences occur between things and between their names.